package com.phei.netty.protocol.http.xml.codec;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageEncoder;
import org.jibx.runtime.BindingDirectory;
import org.jibx.runtime.IBindingFactory;
import org.jibx.runtime.IMarshallingContext;

import java.io.StringWriter;
import java.nio.charset.Charset;

public abstract class AbstractHttpXmlEncoder<T> extends MessageToMessageEncoder<T> {
    IBindingFactory factory = null;
    StringWriter writer = null;
    static final String CHARSET_NAME = "UTF-8";

    final static Charset UTF_8 = Charset.forName(CHARSET_NAME);

    protected ByteBuf encode0(ChannelHandlerContext ctx, Object body) throws Exception {
        factory = BindingDirectory.getFactory(body.getClass());
        writer = new StringWriter();
        IMarshallingContext marshallingContext = factory.createMarshallingContext();
        marshallingContext.setIndent(2);
        marshallingContext.marshalDocument(body, CHARSET_NAME, null, writer);
        String xmlStr = writer.toString();
        writer.close();;
        writer = null;
        ByteBuf encodeBuf = Unpooled.copiedBuffer(xmlStr, UTF_8);
        return encodeBuf;
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        if (writer != null) {
            writer.close();
            writer = null;
        }
    }
}
